As the advancement of the aging society in recent years, the number of patients suffering from inflammatory diseases such as cancers, lifestyle related diseases and circulatory diseases is increasing, and as a result, there arises a social problem of, for example, the increase of medical expenses. In order to solve the problem, there is a demand for a diagnostic method with which an inflammatory disease can be detected at an early stage or an effective treatment method with which an inflammatory disease can be cured before becoming severe. An inflammatory disease is considered to be caused and become serious when inflammation becomes chronic. There are, however, many unknown parts in the chronic inflammation, and the mechanism has not been clarified yet. Therefore, studies for purpose of clarifying the mechanism of the chronic inflammation are being earnestly prosecuted inside and outside Japan.
As one of cell types playing a significant role in the chronic inflammation, attention is recently paid to macrophage, that is, a type of leucocytes. It is currently known that there are at least two subtypes of macrophage, that is, one having a function to accelerate inflammation (M1 macrophage) and one having a function to inhibit inflammation (M2 macrophage).
It has been revealed that the macrophage subtypes (hereinafter referred to merely as the subtypes; herein, the term “subtype” refers to the macrophage subtype) are significantly related to pathologic change in inflammatory diseases such as cancer, type II diabetes mellitus related to fatness, arterial sclerosis, and nephritis. There are a large number of reports on the relation between the subtype and the pathology. For example, it is known that the number, the density, the balance or the like of the subtypes reflects the pathology. Accordingly, identification of a subtype is expected to be applied to diagnosis and treatment.
As a method for identifying a subtype, a method in which a fluorescent dye-labeled antibody is used for identifying a protein marker specifically expressed on cell surfaces of each subtype (hereinafter referred to as the fluorescent antibody method) is known (NPL 1).
On the other hand, an exemplified method in which a porphyrin compound is used to be specifically incorporated into macrophages infiltrated into an inflammatory site in a pancreatic island is disclosed (PTL 1).
If identification and evaluation of a subtype, and evaluation, analysis and screening of influence of a substance on the subtype can be simply performed, the roles of the subtype played in an inflammatory disease will be understood in more detail. An effective diagnostic method for an inflammatory disease can be expected to be developed based on the identification and evaluation of the subtype. Besides, if the subtype is controlled in a disease site or a specific subtype having been adjusted in vitro is administered based on the identification, evaluation, analysis and screening of the subtype, an early treatment method for the inflammatory disease can be developed.